The proposed research on the basal lamina (BL) of stratified squamous epithelium (SSE) involves the following: 1. Isolation of SSE-BL from human oral mucosa and skin using a variety of denaturing and reducing agents to accomplish selective solubilization. 2. Purification of the individual BL proteins using a combination of ion exchange chromatography, gel filtration and immunoadsorption. 3. Elucidation of the major chemical and physiocochemical properties of the purified proteins. 4. Immunological characterization of BL from bovine oral mucosa and human skin using immunohistochemical, immunocytochemical, immunochemical and immunoelectrophoretic techniques. Immunological identity and cross-reaction with basal laminae from homologous and heterologous tissues and species will be determined. Ultrastructural localization of the antigenic determinants of BL will be established using immuno-electron microscopy with peroxidase and ferritin conjugated antibody. BL synthesis in healing wounds of the oral mucosa and skin will be studied by fluorescent antibody and immuno-electron microscopic techniques. 5. Investigation of BL changes in a group of diseases which manifest their pathology in the mucosa of the oral cavity, including: squamous cell carcinoma, bullous and benign mucous membrane pemphigoid and adenocystic carcinoma.